Model:BITM

BITM

BITM Questionnaire

Contact Information

Model:	BITM
Contact person:	Riccardo Masetti
Institute:	University of Bologna
City:	Bologna
Country:	Italy
Email:	riccardo.masetti@tele2.it
2nd person involved:	Sergio Fagherazzi (Project manager)
3rd person involved:	Alberto Montanari (Technical contact)

Model description

Model type:

Single model for the coastal domain.

Description:

BIT Model aims to simulate the dynamics of the principal processes that govern the formation and evolution of a barrier island. The model includes sea-level oscillations and sediment distribution operated by waves and currents. Each process determines the deposition of a distinct sediment facies, separately schematized in the spatial domain. Therefore, at any temporal step, it is possible to recognize six different stratigraphic units: bedrock, transitional, overwash, shoreface aeolian and lagoonal.

Technical information

Supported platforms:	Windows
Programming language:	Fortran77, Fortran90
Model development started at:	2006 and development still takes place.
To what degree will the model become available:	Source code will be available
Current license type:	Free
Memory requirements:	2Gb
Typical run time:	hours

Input / Output description

Input parameters:	Sea level curve; rate of lagoonal deposition; rate of overwash; initial shelf profile. The stratigraphic data are organized in a matrix of integers. Every matrix entry corresponds to a stratigraphic unit (bedrock, overwash, transitional, shoreface, aeolian and lagoonal).
Input format:	ASCII, Binary
Output parameters:	Resultant barrier island configuration and sediment distribution along the continental shelf as results of the effects of five different processes: reworking of the beach profile, inner-shelf sediment redistribution, overwash, laggonal deposition and aeolian sediment reworking.
Output format:	ASCII, Binary
Post-processing software (if needed):	No
Visualization software (if needed):	Yes, Matlab

Process description

Processes represented by model:	BIT Model takes into consideration five different processes: reworking of the beach profile. The model assumes that the wave action reworks the beach profile towards an equilibrium configuration described by the Dean's equation; inner-shelf sediment redistribution, which is the redistribution of sediments beyond the beach toe determined by the bottom shear stresses produced by wind waves; overwas, which is the erosion of sediment along the beach profile and its corresponding deposition on the top of the barrier island or in the back-barrier area. Overwash is related to storm surges produced bt extreme atmospheric events; lagoonal deposition, which is the deposition of fine sediments in the accomodation space between the barrier island and the mainland; aeolian sediment reworking, which represents the wind action on the subaerial part of the island.
Key physical parameters & equations:	The dynamics of erosion and deposition are schematized with a relationship, which represents a diffusion scheme that changes the bottom elevation at a rate linearly proportional to the difference between the current and the equilibrium profile, defined by the Dean's equation, and then redistributes the removed or deposited material in equal parts between the contiguous inshore and offshore locations. The phenomenon of overwash is schematized assuming that the first shoreface element of the barrier island is eroded of a quantity, which is related to the frequency of hurricanes and severe storms and to the difference between the maximum elevation of the barrier and the mean sea level.
Length scale & resolution constraints:	Vertically: cm to m, Horizontally: 50 m to 30 km
Time scale & resolution constraints:	Millennial scale
Numerical limitations and issues :	--

Testing

Available calibration data sets:	--
Available test data sets:	In order to verify the millennial-scale evolution of a barrier island, it is necessary to know the sea level curve, the rate of lagoonal deposition, the rate of overwash and the initial shelf profile. The BIT Model has been applied to the shelf profile in front of Sand Key, Florida.
Ideal data for testing:	It would be interesting to have grainsize data in addition to the other data.

User groups

Currently or plans for collaborating with:

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Documentation

Key papers of the model:	Masetti, R., Fagherazzi, S., Montanari, A., 2008. Application of a barrier island translation model to the millennial-scale evolution of Sand Key, Florida. Continental Shelf Research 28, 1116-1126.
Is there a manual available:	no
Model website if any:	no

Additional comments

Comments:

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